268 research outputs found
Automated System for Early Breast Cancer Detection in Mammograms
The increasing demand on mammographic screening for early breast cancer detection, and the subtlety of early breast cancer signs on mammograms, suggest an automated image processing system that can serve as a diagnostic aid in radiology clinics. We present a fully automated algorithm for detecting clusters of microcalcifications that are the most common signs of early, potentially curable breast cancer. By using the contour map of the mammogram, the algorithm circumvents some of the difficulties encountered with standard image processing methods. The clinical implementation of an automated instrument based on this algorithm is also discussed
The Extrasolar Planet epsilon Eridani b - Orbit and Mass
Hubble Space Telescope observations of the nearby (3.22 pc), K2 V star
epsilon Eridani have been combined with ground-based astrometric and radial
velocity data to determine the mass of its known companion. We model the
astrometric and radial velocity measurements simultaneously to obtain the
parallax, proper motion, perturbation period, perturbation inclination, and
perturbation size. Because of the long period of the companion, \eps b, we
extend our astrometric coverage to a total of 14.94 years (including the three
year span of the \HST data) by including lower-precision ground-based
astrometry from the Allegheny Multichannel Astrometric Photometer. Radial
velocities now span 1980.8 -- 2006.3. We obtain a perturbation period, P = 6.85
+/- 0.03 yr, semi-major axis, alpha =1.88 +/- 0.20 mas, and inclination i =
30.1 +/- 3.8 degrees. This inclination is consistent with a previously measured
dust disk inclination, suggesting coplanarity. Assuming a primary mass M_* =
0.83 M_{\sun}, we obtain a companion mass M = 1.55 +/- 0.24 M_{Jup}. Given the
relatively young age of epsilon Eri (~800 Myr), this accurate exoplanet mass
and orbit can usefully inform future direct imaging attempts. We predict the
next periastron at 2007.3 with a total separation, rho = 0.3 arcsec at position
angle, p.a. = -27 degrees. Orbit orientation and geometry dictate that epsilon
Eri b will appear brightest in reflected light very nearly at periastron.
Radial velocities spanning over 25 years indicate an acceleration consistent
with a Jupiter-mass object with a period in excess of 50 years, possibly
responsible for one feature of the dust morphology, the inner cavity
MOST discovers a multimode delta Scuti star in a triple system: HD 61199
A field star, HD 61199 (V ~ 8), simultaneously observed with Procyon by the
MOST (Microvariability & Oscillations of STars) satellite in continuous runs of
34, 17, and 34 days in 2004, 2005, and 2007, was found to pulsate in 11
frequencies in the delta Scuti range with amplitudes from 1.7 down to 0.09
mmag. The photometry also showed variations with a period of about four days.
To investigate the nature of the longer period, 45 days of time-resolved
spectroscopy was obtained at the Thueringer Landessternwarte Tautenburg in
2004. The radial velocity measurements indicate that HD 61199 is a triple
system. A delta Scuti pulsator with a rich eigenspectrum in a multiple system
is promising for asteroseismology. Our objectives were to identify which of the
stars in the system is the delta Scuti variable and to obtain the orbital
elements of the system and the fundamental parameters of the individual
components, which are constrained by the pulsation frequencies of the delta
Scuti star. Classical Fourier techniques and least-squares multi-sinusoidal
fits were applied to the MOST photometry to identify the pulsation frequencies.
The groundbased spectroscopy was analysed with least-squares-deconvolution
(LSD) techniques, and the orbital elements derived with the KOREL and ORBITX
routines. Asteroseismic models were also generated. The photometric and
spectroscopic data are compatible with a triple system consisting of a close
binary with an orbital period of 3.57 days and a delta Scuti companion (HD
61199,A) as the most luminous component. The delta Scuti star is a rapid
rotator with about vsin i = 130 km/s and an upper mass limit of about 2.1 Msun.
For the close binary components, we find they are of nearly equal mass, with
lower mass limits of about 0.7 Msun.Comment: 11 pages, 14 figures, accepted by A&
Structure and Evolution of Nearby Stars with Planets. I. Short-Period Systems
Using the Yale stellar evolution code, we have calculated theoretical models
for nearby stars with planetary-mass companions in short-period nearly circular
orbits: 51 Pegasi, Tau Bootis, Upsilon Andromedae, Rho Cancri, and Rho Coronae
Borealis. We present tables listing key stellar parameters such as mass,
radius, age, and size of the convective envelope as a function of the
observable parameters (luminosity, effective temperature, and metallicity), as
well as the unknown helium fraction. For each star we construct best models
based on recently published spectroscopic data and the present understanding of
galactic chemical evolution. We discuss our results in the context of planet
formation theory, and, in particular, tidal dissipation effects and stellar
metallicity enhancements.Comment: 48 pages including 13 tables and 5 figures, to appear in Ap
1958: Abilene Christian College Bible Lectures - Full Text
“GOD”
Being the
Abilene Christian College Annual
Bible Lectures
1958
Price: $3.00
Published by
FIRM FOUNDATION PUBLISHING HOUSE
Box 77 Austin, Texa
Epigenetic Patterns Maintained in Early Caenorhabditis elegans Embryos Can Be Established by Gene Activity in the Parental Germ Cells
Epigenetic information, such as parental imprints, can be transmitted with genetic information from parent to offspring through the germ line. Recent reports show that histone modifications can be transmitted through sperm as a component of this information transfer. How the information that is transferred is established in the parent and maintained in the offspring is poorly understood. We previously described a form of imprinted X inactivation in Caenorhabditis elegans where dimethylation on histone 3 at lysine 4 (H3K4me2), a mark of active chromatin, is excluded from the paternal X chromosome (Xp) during spermatogenesis and persists through early cell divisions in the embryo. Based on the observation that the Xp (unlike the maternal X or any autosome) is largely transcriptionally inactive in the paternal germ line, we hypothesized that transcriptional activity in the parent germ line may influence epigenetic information inherited by and maintained in the embryo. We report that chromatin modifications and histone variant patterns assembled in the germ line can be retained in mature gametes. Furthermore, despite extensive chromatin remodeling events at fertilization, the modification patterns arriving with the gametes are largely retained in the early embryo. Using transgenes, we observe that expression in the parental germline correlates with differential chromatin assembly that is replicated and maintained in the early embryo. Expression in the adult germ cells also correlates with more robust expression in the somatic lineages of the offspring. These results suggest that differential expression in the parental germ lines may provide a potential mechanism for the establishment of parent-of-origin epigenomic content. This content can be maintained and may heritably affect gene expression in the offspring
Baseline characteristics of patients in the reduction of events with darbepoetin alfa in heart failure trial (RED-HF)
<p>Aims: This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes.</p>
<p>Methods and results: Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate <60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106–117) g/L.</p>
<p>Conclusion: The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity.</p>
- …